Intraocular Pressure Adjustment Based on Estimated Patient Eye Level Distance

Maintaining intraocular pressure (IOP) within a desired range is an important factor during ophthalmic surgical interventions including, for example, refractive surgery, lens-replacement surgery, and retinal surgery. During surgical interventions, an ophthalmic surgical system uses infusion pressure to deliver an irrigation fluid into the interior of the eye, and the ophthalmic surgical system uses aspiration (vacuum) pressure to remove vitreous and lens fragments from the interior of the eye. The infusion pressure and the aspiration pressure dictate the resultant IOP.

Aspects of the present disclosure relate to surgical systems for ophthalmic (eye) procedures, and more specifically, to infusion and aspiration systems for performing ophthalmic procedures.

In certain embodiments, a surgical system includes at least one of an infusion subsystem or an aspiration subsystem, a distance estimation device, and one or more processors. The distance estimation device is configured to estimate a vertical distance between a point of reference associated with the surgical system and a patient eye level (PEL) using light. The point of reference corresponds to a pressure level setting for infusion or aspiration. The one or more processors are configured to execute instructions that cause the one or more processors to receive the vertical distance and cause the at least one of the infusion subsystem or the aspiration subsystem to control an infusion pressure or an aspiration pressure based on the vertical distance to match the pressure level setting at the PEL.

In certain embodiments, a method includes estimating, by a distance estimation device, a vertical distance between a patient eye level (PEL) and a point of reference associated with a surgical system. The point of reference is disposed above or below the PEL and the vertical distance is estimated using light. An amount to increase or an amount to decrease an infusion pressure or an aspiration pressure to match a pressure level setting is computed by one or more processors based on the vertical distance. The infusion pressure or the aspiration pressure is modified by at least one of an infusion subsystem or aspiration subsystem based on the amount to increase or the amount to decrease.

The above summary is not intended to represent every possible embodiment or every aspect of the subject disclosure. Rather the foregoing summary is intended to exemplify some of the novel aspects and features disclosed herein. The above features and advantages, and other features and advantages of the subject disclosure, will be readily apparent from the following detailed description of representative embodiments and modes for carrying out the subject disclosure when taken in connection with the accompanying drawings and the appended claims.

Aspects of the present disclosure relate to surgical systems for ophthalmic (eye) procedures, and more specifically, to infusion and aspiration systems for performing ophthalmic procedures.

The designations “first” and “second” as used herein are not meant to indicate or imply any particular positioning or other characteristic. Rather, when the designations “first” and “second” are used herein, they are used only to distinguish one component from another. The terms “attached,” “connected,” “coupled,” and the like mean attachment, connection, coupling, etc., of one part to another either directly or indirectly through one or more other parts, unless direct or indirect attachment, connection, coupling, etc., is specified.

In order to control the IOP, an infusion pressure level and an aspiration pressure level are provided to the ophthalmic surgical system by a user. The surgical system includes a point of reference which indicates a calibrated elevation at which delivered infusion and aspiration pressure match the user specified infusion and aspiration pressure. Because of gravity, if a patient eye level (PEL) is above the point of reference, then the infusion pressure delivered at the PEL will be less than the user specified infusion pressure and the aspiration pressure delivered at the PEL will be greater than the user specified aspiration pressure. Conversely, if the PEL is below the point of reference, then the infusion pressure delivered at the PEL will be greater than the user specified infusion pressure and the aspiration pressure delivered at the PEL will be less than the user specified aspiration pressure. As used herein, the terms “infusion” and “irrigation” are used interchangeably to denote positive pressure as opposed to aspiration or vacuum pressure. Although the term “infusion” is more commonly used in the context of posterior segment procedures and the term “irrigation” is more commonly used in the context of anterior segment procedures, it is to be appreciated that, as used herein, the terms “infusion” and “irrigation” are interchangeable and the terms are not intended to be limited to a particular type of ophthalmic procedure.

The ophthalmic surgical system compensates for the differences between the specified and delivered pressures by receiving a vertical distance between the PEL and the point of reference as an input from the user. However, the vertical distance is difficult to accurately measure because the PEL and the point of reference are not included in the same vertical plane. If an inaccurate vertical distance is provided to the ophthalmic surgical system, then the specified and delivered pressures will not be the same, which is undesirable.

1 FIG. 100 100 102 102 103 104 106 103 108 102 110 112 102 112 102 illustrates an example surgical environment, according to embodiments described herein. As shown, the surgical environmentincludes an ophthalmic surgical system. The ophthalmic surgical systemis illustrated to include a console, a display device, and a traycoupled to the consoleby a mechanical arm. In some embodiments, the ophthalmic surgical systemincludes a cassettewhich indicates a point of referencefor infusion and aspiration pressure supplied by the ophthalmic surgical system. The point of referencecorresponds to an elevation from the ground at which the infusion and aspiration pressure supplied matches infusion and aspiration pressure levels specified by a user of the ophthalmic surgical system.

104 112 112 112 Consider an example in which the user interacts with a user interface displayed by the display deviceto specify an infusion (irrigation) pressure of 25 mmHg (millimeters of mercury) and an aspiration (vacuum) pressure of 150 mmHg. In this example, if the infusion and aspiration are delivered at an elevation that is above the point of reference, then the delivered infusion (irrigation) pressure will be less than 25 mmHg and the delivered aspiration (vacuum) pressure will be greater than 150 mmHg due to the force of gravity (e.g., the aspiration zero set point will be offset by the equivalent gravity amount). Accordingly, the force of gravity is subtractive to the infusion pressure and additive to the aspiration pressure for the delivery elevation that is above the point of reference. Conversely, if the infusion and aspiration are delivered at an elevation that is below the point of reference, then the delivered infusion (irrigation) pressure will be greater than 25 mmHg and the delivered aspiration (vacuum) pressure will be less than 150 mmHg due to the force of gravity.

112 112 102 102 102 112 112 112 102 102 102 112 Continuing the example above, if a first distance between the point of referenceand the elevation that is above the point of referenceis known and provided as an input to the ophthalmic surgical system, then the ophthalmic surgical systemis capable of adjusting the infusion pressure and the aspiration pressure to compensate for the first distance. For example, one or more processors of the ophthalmic surgical systemcan execute instructions which cause an infusion subsystem to increase the infusion pressure and an aspiration subsystem to decrease the aspiration pressure such that the delivered infusion pressure will be 25 mmHg and the delivered aspiration pressure will be 150 mmHg at the elevation that is above the point of reference. Similarly, if a second distance between the point of referenceand the elevation that is below the point of referenceis known and provided as an input to the ophthalmic surgical system, then the ophthalmic surgical systemis capable of adjusting the infusion pressure and the aspiration pressure to compensate for the second distance. For example, the one or more processors of the ophthalmic surgical systemcan execute instructions which cause the infusion subsystem to decrease the infusion pressure and the aspiration subsystem to increase the aspiration pressure such that the delivered infusion pressure will be 25 mmHg and the delivered aspiration pressure will be 150 mmHg at the elevation that is below the point of reference.

1 FIG. 1 FIG. 1 FIG. 1 FIG. 114 112 120 112 116 112 116 112 116 120 112 110 114 120 116 112 112 116 120 112 116 120 112 116 further illustrates a patienthaving a corresponding patient eye level (PEL) 116 which, in the example of, is below the point of reference. A vertical distancebetween the point of referenceand the PELis shown inrelative to projections of the point of referenceand the PEL. Notably, the projections of the point of referenceand the PELare not available in a physical surgical environment but are included into illustrate the challenges of accurately measuring the vertical distance. In particular, the point of referencedepicted on the cassetteand the patientdo not share a vertical plane. As a result, in order to measure the vertical distance, a location of the PELmay be estimated in a vertical plane that includes the point of referenceor a location of the point of referencemay be estimated in a vertical plane that includes the PEL. The vertical distancemay then be estimated/measured between the estimated location (which may be inaccurate) and the point of referenceor the PEL. However, even if the estimated location is accurate, the value estimated/measured for the vertical distancewill likely be inaccurate because of the difficulty in measuring between something which can be visually perceived (e.g., the point of referenceor the PEL) and something that cannot be visually perceived (e.g., the estimated location).

2 FIG.A 2 FIG.A 103 202 120 112 116 202 103 110 202 102 202 106 103 108 202 114 illustrates a first example system for estimating a distance, according to embodiments described herein. In the embodiments of, the consoleincludes a distance estimation deviceconfigured for use in estimating the vertical distancebetween the point of referenceand the PEL. In the illustrated example, the distance estimation deviceis included in the consoleadjacent to the cassette. For example, the distance estimation devicecan be embedded in a portion of the ophthalmic surgical system. However, in some embodiments, the distance estimation deviceis disposed on the trayor included in a dedicated mechanical arm that is coupled to the consolesuch as the mechanical arm. In some embodiments, the distance estimation devicemay be disposed on or adjacent to the patient.

202 120 202 120 202 202 202 202 202 a b a b In some embodiments, the distance estimation deviceis configured to estimate the vertical distanceusing light. For example, the distance estimation devicemay include a laser level (or another laser device configured to propagate laser light) which estimates the vertical distance. In some embodiments, the distance estimation deviceincludes a laser and electromechanical components,. In some embodiments, the electromechanical componentincludes a first actuator that is configured to actuate the laser of the laser level up or down. In some embodiments, the electromechanical componentincludes a second actuator that is configured to actuate the laser of the laser level left or right.

202 116 202 202 202 102 116 116 203 203 203 203 120 203 203 120 a b a b c a b c In some embodiments, the distance estimation deviceprojects laser light (e.g., red laser light, green laser light, etc.) from the laser of the laser level to the PEL. In some embodiments, the electromechanical components,adjust an orientation of the distance estimation devicerelative to the ophthalmic surgical systemto align the laser light with the PEL. When the laser light is aligned with the PEL, the laser level measures a distance(d), an angle(α), and/or an angle(β). As shown, the distanceis representative of a hypotenuse of a right triangle, and the vertical distancecorresponds to an adjacent side relative to the angleand an opposite side relative to the angle. In some embodiments, the vertical distanceis computable as d*cos α and/or d*sin β.

120 202 120 102 102 116 116 After estimating the vertical distance, the distance estimation deviceprovides the vertical distanceas an input to the ophthalmic surgical system. In some embodiments, one or more processors of the ophthalmic surgical systemexecute instructions which cause the infusion subsystem to adjust infusion pressure such that infusion pressure delivered to the PELmatches an infusion pressure level specified by the user. In some embodiments, the instructions executed by the one more processors cause the aspiration subsystem to adjust aspiration pressure such that aspiration pressure delivered to the PELmatches an aspiration pressure level specified by the user. Notably, the infusion pressure and the aspiration pressure are maintained after adjustment.

2 FIG.B 2 FIG.A 200 202 200 104 200 204 103 103 116 illustrates a first example user interfacethat may be used in conjunction with the distance estimation deviceof, according to embodiments described herein. In the illustrated example, the first example user interfaceis displayed by the display deviceto facilitate control of the laser level. As shown, the first example user interfaceincludes a user interface elementfor adjusting an orientation of the laser level relative to the console. Adjusting the orientation of the laser level relative to the consoleadjusts a direction of laser light emitting from the laser level relative to the PEL.

204 202 103 116 204 202 103 116 204 202 103 116 204 202 103 116 a a b a c b d b For example, a user interaction with user interface elementcauses the electromechanical componentto actuate the orientation of the laser level up relative to the console(and adjusts the direction of the laser light emitting from the laser level up relative to the PEL). A user interaction with user interface elementcauses the electromechanical componentto actuate the orientation of the laser level down relative to the console(and adjusts the direction of the laser light emitting from the laser level down relative to the PEL). A user interaction with user interface elementcauses the electromechanical componentto actuate the orientation of the laser level towards the left relative to the console(and adjusts the direction of the laser light emitting from the laser level towards the left relative to the PEL). A user interaction with user interface elementcauses the electromechanical componentto actuate the orientation of the laser level towards the right relative to the console(and adjusts the direction of the laser light emitting from the laser level towards the right relative to the PEL).

116 206 203 203 203 202 102 120 203 203 203 102 208 104 208 2 FIG.A a b c a b c In some embodiments, when the laser light emitting from the laser level is aligned with the PELas illustrated in, a user interaction with user interface elementcauses the laser level to measure the distance(d), the angle(a) and/or the angle(B). In some embodiments, the distance estimation deviceand/or the one or more processors of the ophthalmic surgical systemcompute the vertical distancebased on the distance(d), the angle(a) and/or the angle(B). As shown, the one or more processors of the ophthalmic surgical systemexecute instructions which cause the one or more processors to render an indicationfor display by the display device. In the illustrated example, the indicationstates “Vertical distance is approximately 12 inches.”

200 210 210 120 210 102 116 102 116 112 In some embodiments, the first example user interfacemay include a user interface elementsuch that a user interaction with the user interface elementconfirms that the vertical distanceis about 12 inches. In some embodiments, the user interaction with the user interface elementcauses the one or more processors of the ophthalmic surgical systemto execute instructions which cause the infusion subsystem and the aspiration subsystem to adjust the infusion and aspiration pressure supplied to the PEL, respectively, to match infusion and aspiration pressure levels specified by the user of the ophthalmic surgical system. Since the PELis below the point of reference, the one or more processers can cause the infusion subsystem to decrease the infusion (irrigation) pressure by about 1.868 mmHg per inch of the 12 inches or by about 22.416 mmHg in total. Conversely, the one or more processors can cause the aspiration subsystem to increase the aspiration (vacuum) pressure by about 1.868 mmHg per inch of the 12 inches or by about 22.416 mmHg in total.

103 204 103 103 202 202 103 102 a b Note that although adjusting the orientation of the laser level relative to the consoleis described with respect to the user interface element, it is to be appreciated that, in some embodiments, the orientation of the laser level relative to the consoleis adjusted differently. In some embodiments, the orientation of the laser level relative to the consolemay be adjusted by controlling the electromechanical components,using an electromechanical system (e.g., a joystick). In some embodiments, the orientation of the laser level relative to the consolecan be adjusted manually (e.g., by the user of the user of the ophthalmic surgical system).

3 FIG.A 3 FIG.A 103 302 120 100 302 302 302 a b illustrates a second example system for of estimating a distance, according to embodiments described herein. In the embodiments of, the consoleincludes a distance estimation devicewith a light detection and ranging (LIDAR) system which estimates the vertical distanceby three-dimensionally mapping the surgical environment. In the illustrated example, the distance estimation deviceincludes one light transmitterand one light receiver. Although, it is to be appreciated that the LIDAR system can include multiple light transmitters and multiple light receivers.

100 302 302 302 100 100 302 100 100 a b The LIDAR system maps the surgical environmentby transmitting light via the light transmitter, detecting reflected light via the light receiver, and measuring time between the transmission and the reflection of the light. In some embodiments, the distance estimation devicecomputes a three-dimensional map of the surgical environmentbased on time between the transmission and the reflection of the light. After computing the three-dimensional map of the surgical environment, the distance estimation deviceis capable of computing distances between any portions of the surgical environmentby computing distances between three-dimensional coordinates corresponding to the portions of the surgical environment.

302 120 302 120 100 100 In some embodiments, the distance estimation deviceis not limited to estimating the vertical distanceusing light. For example, the distance estimation deviceincludes a millimeter wavelength radar system which estimates the vertical distanceby three-dimensionally mapping the surgical environment. The millimeter wavelength radar system maps the surgical environmentby transmitting millimeter wavelength radar waves, detecting reflected millimeter wavelength radio waves, and measuring time between the transmission and the reflection of the millimeter wavelength radar waves.

3 FIG.B 3 FIG.A 300 300 104 300 304 100 illustrates a second example user interface, according to embodiments described herein. As shown, the second example user interfaceis displayed by the display device, which can facilitate distance estimation using the light detection and ranging (LIDAR) system and/or the millimeter wavelength radar system of. In some embodiments, the second example user interfaceincludes a three-dimensional mapof the surgical environmentgenerated by the LIDAR system and/or the millimeter wavelength radar system.

306 104 102 104 304 308 116 102 112 112 102 An indicationis displayed by the display devicethat states “Please indicate PEL in the 3D environment below.” In some embodiments, the user of the ophthalmic surgical systeminteracts with the display devicerelative to the three-dimensional mapto provide an indicationof a location of the PEL. In some embodiments, the user of the ophthalmic surgical systemmay also indicate a location of the point of referenceor an elevation of the point of referencecan be predetermined by the one or more processors of the ophthalmic surgical system.

102 308 120 308 112 208 104 102 210 120 210 102 116 102 In some embodiments, the one or more processors of the ophthalmic surgical systemexecute instructions which cause the one or more processors to project two-dimensional coordinates of the indicationinto three-dimensional coordinates in the three-dimensional map (e.g., by ray casting). The instructions executed by the one or more processors cause the one or more processors to estimate the vertical distancebased on the three-dimensional coordinates projected according to the indicationand three-dimensional coordinates of the point of reference. In some embodiments, the one or more processors render the indicationfor display by the display devicewhich states “Vertical distance is approximately 12 inches.” In some embodiments, the user of the ophthalmic surgical systeminteracts with the user interface elementto confirm that the vertical distanceis about 12 inches. In various embodiments, the user's interaction with the user interface elementcauses the one or more processors of the ophthalmic surgical systemto cause the infusion subsystem and the aspiration subsystem adjust the infusion and aspiration pressure supplied to the PEL, respectively, to match the infusion and aspiration pressure levels specified by the user of the ophthalmic surgical system.

4 FIG. 3 FIG.A 400 300 400 400 304 100 304 100 402 404 116 404 402 116 402 404 114 404 116 illustrates a third example user interface, according to embodiments described herein. Similarly to the second example user interface, the third example user interfacefacilitates distance estimation using the LIDAR system and/or the millimeter wavelength radar system described in relation to. In the illustrated example, the third example user interfaceincludes the three-dimensional mapof the surgical environmentgenerated by the LIDAR system and/or the millimeter wavelength radar system. As shown in the three-dimensional map, the surgical environmentincludes a drapeand a target such as a detectable tagat the PEL. In some embodiments, the detectable tagis a colored or marked sticker placed on the drapeat the PELbefore performing an ophthalmic surgical procedure and removed from the drapeafter performing the ophthalmic surgical procedure. In some embodiments, the detectable tagmay include a barcode or a QR code. In some embodiments, the target includes a trocar cannula (e.g., inserted in an eye of the patientin addition or alternative to the detectable tag). In some embodiments, the trocar cannula is detected to indicate the PEL.

404 102 404 112 120 406 406 208 104 102 210 120 210 102 116 102 In some embodiments, upon detecting the detectable tag, the one or more processors of the ophthalmic surgical systemexecute instructions which cause the one or more processors to use a location of the detectable tagand the location of the point of referenceto compute the vertical distanceand display an indication. As shown, the indicationstates “Tag detected.” In some embodiments, the instructions executed by the one or more processors cause the one or more processors to render the indicationfor display by the display devicewhich states “Vertical distance is approximately 12 inches.” In some embodiments, the user of the ophthalmic surgical systeminteracts with the user interface elementto confirm that the vertical distanceis about 12 inches. In some embodiments, by interacting with the user interface element, the user causes the one or more processors of the ophthalmic surgical systemto cause the infusion subsystem and the aspiration subsystem to adjust the infusion and aspiration pressure supplied to the PEL, respectively, to match the infusion and aspiration pressure levels specified by the user of the ophthalmic surgical system.

5 FIG.A 2 3 FIGS.A andA 500 500 500 104 503 500 504 506 508 506 506 508 508 illustrates an example of a surgical console, according to embodiments described herein. Surgical consolemay be any of the surgical consoles illustrated and described in relation to. As shown, the surgical consoleincludes the display deviceand a distance estimation device. The surgical consoleis illustrated to include a computerhaving a processorand a memory. The processoris representative of a variety of types of processors such as central processing units (CPUs), graphics processing units (GPUs), processors implemented using field-programmable gate arrays (FPGAs) (e.g., a soft processors), accelerators, etc. In some embodiments, the processorincludes multiple processors. The memoryincludes volatile and/or non-volatile memory. In some embodiments, the memoryincludes one or more computer readable media storing executable instructions.

503 504 503 120 504 506 506 510 512 120 510 512 514 516 518 510 512 520 522 524 In some embodiments, the distance estimation deviceis communicatively coupled to the computer. The distance estimation devicecommunicates the vertical distanceto the computer, and the processorexecutes instructions that cause the processorto control an infusion subsystemand an aspiration subsystembased on the vertical distance. The infusion subsystemcontrols the infusion pressure and the aspiration subsystemcontrols the aspiration pressure. An input devicesuch as a footswitch is communicatively coupled to an input subsystem. A handpieceis coupled to the infusion subsystemand the aspiration subsystemas well as a generator subsystem(e.g., for RF diathermy), a laser subsystem(e.g., for photocoagulation), and an illumination subsystem(e.g., for intraocular illumination).

5 FIG.B 2 FIG.A 503 509 507 503 202 509 202 202 a b. illustrates an example schematic diagram of a distance estimation devicethat includes electromechanical componentsand a laser. In some embodiments, the distance estimation devicecorresponds to the distance estimation deviceof. For example, the electromechanical componentsinclude the electromechanical components,

5 FIG.C 503 505 503 302 505 302 302 a b. illustrates an example schematic diagram of a distance estimation devicethat includes LIDAR transmitters/receivers. In some embodiments, the distance estimation devicecorresponds to the distance estimation device. In some embodiments, the LIDAR transmitters/receiversinclude the light transmitterand the light receiver

6 FIG. 600 602 120 116 112 102 202 302 illustrates an example methodfor adjusting infusion pressure or aspiration pressure, according to embodiments described herein. At operation, a vertical distance between a patient eye level (PEL) and a point of reference associated with a surgical system is estimated by a distance estimation device using light, the point of reference disposed above or below the PEL. In some embodiments, the vertical distancebetween the PELand the point of referenceon the ophthalmic surgical systemis estimated by the distance estimation deviceusing the laser level or by the distance estimation deviceusing the light detection and ranging (LIDAR) system.

604 506 510 120 506 512 120 At operation, an amount to increase or an amount to decrease an infusion pressure or an aspiration pressure to match a pressure level setting is computed by one or more processors of the surgical system based on the vertical distance. For example, the processorcomputes the amount of infusion pressure for the infusion subsystemto increase or decrease to match the infusion pressure level setting based on the vertical distance. Alternatively or additionally, the processorcomputes the amount of aspiration pressure for the aspiration subsystemto increase or decrease to match the aspiration pressure level setting based on the vertical distance.

606 512 506 510 512 At operation, the infusion pressure or the aspiration pressure is modified by the aspiration subsystembased on the amount to increase or the amount to decrease. In some embodiments, the processorexecutes instructions which cause the infusion subsystemto modify the infusion pressure or the aspiration subsystemto modify the aspiration pressure based on the amount to increase or the amount to decrease.

The disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents and shall not be restricted or limited by the foregoing detailed description.